<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>11-盒子模型</title>
    <style>
        .box{
            width: 600px;
            height: 600px;
            border-left: 10px dashed red;
            border-right: 10px dashed blue;
            border-top: 10px dashed orange;
            border-bottom: 10px dashed black;
            margin: 30px auto;
            /* 内边距padding让图片居中 */
            padding-left: 180px;
            padding-top: 180px;
            /* 设置内边距之后，保证盒子的宽高不发生改变 */
            box-sizing: border-box;
        }
    </style>
</head>
<body>
    <!-- 
        pxcook
        ps
     -->
    <div class="box">
        <img src="images/200.png" alt="">
    </div>
</body>
</html>